Rail transport plays a key role in the transport of passengers and goods. The high demand for effective means of flaw detection of high-speed rails, which is an important component of railway safety, is justified by the constantly growing number of vehicles and their speed [2]. Failure of elements of the railway infrastructure entails huge losses. In this regard, the analysis and forecasting of the state of elements of the railway infrastructure is an urgent task. This article analyzes modern methods for diagnosing the state of a rail track from a mobile bogie or a conventional locomotive. A method for diagnostics of a rail track is proposed, based on registration of vibrations near the rolling surface of rails and processing these signals using neural networks.
Keywords: rail flaw detection, wheel surface, algorithm, IMM, MEMS, control system, inertial sensor, rail defect, contactless measurement
The urgency of estimating the content of nitrates in food products to ensure environmental safety at an individual level is discussed in the article. Data on the negative effect of increased nitrate content in plant foods on human health are given. The results of the study on the determination of the content of nitrates in food products using a household nitrate counter "Soek nuk-019-2" are discussed. This device makes a conclusion about the concentration of nitrates by comparing the reference electrical conductivity of different types of vegetables / fruits with the electrical conductivity of a particular controlled product. It is determined that exceeding the MPC is observed in potatoes and onions, which are sold through a network of stores that occupy leading positions in the prevalence in Taganrog. Excess of MAC in carrots is observed only in its central part (core). Based on the results obtained, practical recommendations are given to ensure the safety of food consumption.
Keywords: food safety, food, nitrate content, household nitrate
The method of calculating the effect of thermal stress on the dynamic characteristics of inertial microelectromechanical systems (MEMS) is presented in this article. Testing was conducted on a technique of vibrating gyroscope LL type electrostatic actuator in a temperature range from -40 to 80 ° C. It is shown that the thermoelastic stresses lead to a shift in the natural oscillation frequencies and the change of amplitude-frequency characteristics of the system. Method of calculation is based on the sequential solution of differential equations of heat conduction and the generalized Hooke's law, taking into account thermal stresses. Modal analysis and construction of MEMS amplitude-frequency characteristics is performed considering prestressed calculated in the previous step.
Keywords: microelectromechanical systems, micromechanical gyroscope, thermoelastic stresses, temperature errors, numerical simulation, frequency response
The work is devoted to the synthesis of a linear acceleration sensor with two axes of sensitivity behavioral model based on the mathematical model of this device in the differential equations form using MatLab software package Simulink environment. The results of the dynamics simulation of the synthesized behavioral sensor model in the form of transient and spectral analysis of the system reaction are shown. The main idea of analysis is to study the frequency parameters and damping properties of the object. The experiment has identified high quality factor of the oscillatory system, due to small damping, it is reflected by the slow decay of transient and pronounced resonances.
Keywords: microsystem technology, microelectromechanical systems, electronic components, accelerometer, sensor, design, model, modeling, transient, spectral analysis
The work is devoted to the synthesis of a angular rate sensor behavioral model based on the mathematical model of this device in the differential equations form using MatLab software package Simulink environment. The results of the dynamics simulation of the synthesized behavioral sensor model in the form of transient and spectral analysis of the system reaction are shown. The main idea of analysis is to study the frequency parameters and damping properties of the object. The experiment has identified high quality factor of the oscillatory system, due to small damping, it is reflected by the slow decay of transient and pronounced resonances.
Keywords: microsystem technology, microelectromechanical systems, electronic components, gyroscope, electrostatics, design, model, modeling, transient, spectral analysis
The paper describes the development and research of MEMS sensors error model using experimental data approximation of fourth degree polynomial with coefficients computed by least square method and written using of graphical programming language LabVIEW
Keywords: Navigation, MEMS sensors, error model.
Developed criteria for matching the oscillation frequencies of sensitive elements biaxial functionally integrated micromechanical gyroscopes-accelerometers LL-type. Review the results of modeling.
Keywords: microsystm technology, element base, model, modeling, gyroscope, accelerometer, sensor
Information about authors of issue №2 (2014)
Keywords: authors
This article reviews systems of respiratory activity registration in relation to sports medicine. Attention is devoted to the use of miniature accelerometers that record the movement of the chest, as the optimal method for the diagnosis of the respiratory parameters. Other methods are based on piezo-resistive sensors, pressure and airflow sensors, and airways resistance sensors. The authors' developed device based on three-axis accelerometer is proposed. It recognizes episodes of apnea with sufficient accuracy for long-term monitoring. The algorithm of the accelerometer data processing is described. In order to minimize noise impact on the useful signal it is necessary to transform the three-dimensional cloud of accelerometer data into a flat sector. Then the relation of gravity vector deviation angle and the nominal position in time is determined. This presented device due to its ability to transmit data via Bluetooth technology, after appropriate software development for mobile phone and the receiving terminal of medical professional, will be able to organize a simple ergonomic long-term remote monitoring of respiratory activity.
Keywords: systems of respiratory activity registration, long-term remote monitoring, three-axis accelerometer
Results of research of influence of processing operations of Nd:YAG of the laser are presented in article, such as the speed of scanning and power of a laser beam on maximum temperature and the thermodeformed status in structure dye-sensitized solar cell. Dependences a component of a tensor of tension are received at various processing operations by means of numerical experiment. Results of researches showed that in intense the deformed status is depend on temperature gradient more, then on coefficients of linear expansion of structure which in this structure differ slightly.
Keywords: laser technologies, thermodeformed, numerical simulation
The method of digital parametric measurement of the phase shift of signals with slowly varying amplitudes of the same slowly varying instantaneous frequencies was proposed. The numerical simulations and experiments on the developed hardware and software system were carried out. The error of measurement the phase difference of harmonic signals in the experiments were not more than 0,00001 radian. The method can be used in applications where the measured value is expressed in terms of the phase difference of quasi-harmonic signals.
Keywords: quasi-harmonic signal, phase shift, real time measurements, hardware and software system
The results of the modeling of joint work of the control system with the aircraft inertial navigation system are represented in this article .For improving the accuracy of the control the results of calibration of inertial sensors with are used. It is shown that the developed method of calibration of inertial sensors with middle accuracy allow to improve the quality of inertial measuring unit and use it in automatically control system of aircraft.
Keywords: aircraft, strapdown inercial navigation system, automatic control system by flight, terminal'nya exactness, algorithmic indemnification
The flight scheduling process is briefly described in the article. It is one of the most important stages of space flight control task solution. Three stages of flight scheduling are given: strategic, tactical and executive. The result of each scheduling phase is presented by special plan type: on-orbit operation summary, weekly lookahead plan, short-term plan. The difference of these plan types is in planning interval and data processing depth. The mathematical modeling of all required data and restrictions is made. A crew downtime minimization is the selected optimization criterion. Modified genetic algorithm for decision of assigned task is designed. The future tasks regarding crew activities scheduling process optimization are defined
Keywords: scheduling, flight operation, crew activities, optimization, mathematical modeling, genetic algorithm
The proposed method of designing hardware components optical switching systems simplifies prototyping and development of systems of optical switching and multi-core VLSI. This method allows to automatically set parameters of the optical system at the design stage, depending on the requirements. This method may be cost-effective at the stage of technical specifications of the project, as will reduce the time required for its coordination between the customer and the design engineer.
At the heart of developing a method of designing systems, optical switching elements is a comprehensive analysis of the equations and functions describing the electrical and optical properties of laser heterostructures, as well as electro-optic modulators and Fabry-Perrot resonators. Fundamental static and dynamic characteristics of semiconductor diode lasers can be calculated by using a set of kinetic equations describing the interaction of electrons, holes and photons in the active layer of the laser structure. At various stages of this method is processing, evaluation and calculation of the main characteristics of the elements of integrated optical switching systems.
Keywords: optical switching, integrated injection laser, quantum-scale heterostructure, amplitude modulation, terahertz range
The model of micromechanical mirrors mobile elements balance is developed. The received results of modelling of a micromechanical mirror are considered.
Keywords: microsystm technology, element base, model, modeling, mirror